If you have been reading about elevated plus maze and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-07-14. Where a claim depends on a specific study, the study is described rather than over-claimed.
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It was designed as a stabilized analogue of tuftsin, a naturally occurring tetrapeptide fragment derived from the immunoglobulin heavy chain. The additional Pro-Gly-Pro segment at the carboxyl terminus is intended to slow enzymatic cleavage. The compound is usually described in the literature as a synthetic peptide with anxiolytic and cognitive-related activity, a label that reflects a research context rather than an approved therapeutic category.
Most published work on selank originates from a small number of research groups in the Russian Federation. A large share of that record appears in Russian-language journals, which limits access for readers who rely on English-indexed databases. Independent replication by laboratories outside the original research network is sparse in publicly available sources. This concentration of origin and language is a frequently noted feature when the compound is summarized in broader reviews of synthetic peptides.
Selank is studied chiefly as an animal-model anxiolytic with proposed secondary effects on memory and immune signaling. Reported mechanisms include modulation of the GABA-A receptor complex, inhibition of enkephalin-degrading enzymes, and shifts in monoamine turnover within limbic structures. Some experiments describe increased expression of brain-derived neurotrophic factor in the hippocampus after repeated dosing. No single molecular target has been confirmed, and the peptide does not bind any receptor with the selectivity typical of a conventional small-molecule drug. Mechanism therefore remains a set of hypotheses rather than an established pathway.
Laboratory work relies on standard behavioral paradigms. Rodents are tested in the elevated plus maze, open field, and passive avoidance tasks, with outcomes compared against diazepam or vehicle controls. Intranasal dosing is used most often because it bypasses first-pass metabolism, though intraperitoneal and intravenous routes also appear in published protocols. Biochemical endpoints include tissue BDNF concentrations, cytokine levels, and monoamine metabolites. Human data are limited to small Russian trials reporting reduced anxiety scores; most were not prospectively registered, and few employed independent outcome assessment.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C33H57N11O9 | Derived from the seven-residue sequence |
| Molecular weight | About 751.9 g/mol | Average mass; the monoisotopic value is slightly lower |
| Residue count | Seven amino acids | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Parent compound | Tuftsin (Thr-Lys-Pro-Arg) | Selank extends tuftsin at the C-terminus |
| Compound class | Synthetic short peptide | Studied in a research setting; not a licensed drug in most markets |
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, frequently abbreviated as TKPRPGP. It was designed as a structural analogue of tuftsin, a naturally occurring tetrapeptide released by enzymatic cleavage of the immunoglobulin heavy chain. The two additional proline residues at the C-terminal end extend the parent chain and change how the molecule behaves in solution. The free peptide has a calculated molecular mass of approximately 751.9 g/mol and is generally supplied as a lyophilised white to off-white powder.
Development work on the compound began in the 1980s and 1990s at the Institute of Molecular Genetics in Moscow, within the same research programme that produced the peptide Semax. Early investigators sought a tuftsin derivative with improved resistance to enzymatic breakdown and with activity in the central nervous system after peripheral administration. Most of the primary literature from this period was published in Russian, a factor that still shapes how easily the findings can be checked by outside groups.
Proposed mechanisms centre on modulation of the GABAergic system, with reports of altered expression of genes related to GABA-A receptor subunits and changed monoamine turnover. Some studies describe inhibition of enkephalinase, the enzyme that degrades endogenous enkephalins, which may prolong opioid peptide signalling. Effects on brain-derived neurotrophic factor and on cytokine expression have also been reported. These findings come largely from animal models and small human studies, and the precise primary target remains unresolved.
Published clinical evidence is limited. Most controlled trials were conducted in Russia, enrolled modest numbers of participants, and appeared in Russian-language journals, which restricts independent verification. Reported outcomes include lower anxiety scores, improved attention and memory measures, and changes in fatigue ratings. Reviews written in English note methodological limitations such as small samples and inconsistent endpoints. Whether the compound produces clinically meaningful benefit relative to established anxiolytics is therefore an open question rather than an established finding.
== M == macroevolution - macromolecular system - macromolecule - macrophage colony-stimulating factor - major histocompatibility complex - Malpighi body - Malpighi layer - marine biology - maslinic acid - mass spectrometer - maturation-promoting factor - mechanoreceptor - medicine - meiosis - melting point - membrane glycoprotein - membrane protein - membrane topology - membrane transport - memory B cell - memory T cell - Mendelian inheritance - metabolic pathway - metabolism - metabotropic glutamate receptor - metalloprotein - metaphase - metazoa - methionine - micelle - Michaelis-Menten kinetics - microbe - microbiology - microevolution - microfilament - microfilament protein - microsatellite - microscope - microtiter plate - microtubule-associated protein - mineralocorticoid receptor - minisatellite - mitochondrial membrane - mitochondrion - mitogen receptor - mitosis - mitotic spindle - mixture - modern evolutionary synthesis - molar volume - mole (unit) - molecular biology - molecular chaperone - molecular dynamics - molecular engineering - molecular evolution - molecular mechanics - molecular modelling - molecular orbital - molecular phylogeny - molecular sequence data - molecule - monoamine - monoclonal antibody - monomer - monosaccharide - monosaccharide transport protein - morphogenesis - morphogenetic field - mos gene - Mössbauer spectroscopy - MRI - MSH - mu opioid receptor - mu-chain immunoglobulin - mucin - Muller's ratchet - multiresistance - muscarinic receptor - muscle - muscle protein - mutagen - mutation - myc gene - mycology - myelin basic protein - myeloma protein - myosin
According to DSST, alcohol causes a decrease in performance on their standardized tests, and caffeine causes a significant improvement. When alcohol and caffeine are consumed jointly, the effects of the caffeine are changed, but the alcohol effects remain the same. For example, consuming additional caffeine does not reduce the effect of alcohol. However, the jitteriness and alertness given by caffeine is decreased when additional alcohol is consumed. Alcohol consumption alone reduces both inhibitory and activational aspects of behavioral control. Caffeine antagonizes the effect of alcohol on the activational aspect of behavioral control, but has no effect on the inhibitory behavioral control. The Dietary Guidelines for Americans recommend avoidance of concomitant consumption of alcohol and caffeine, as taking them together may lead to increased alcohol consumption, with a higher risk of alcohol-associated injury.
== Coupling with THG microscopy == Third-Harmonic Generation (THG) microscopy can be complementary to SHG microscopy, as it is sensitive to the transverse interfaces, and to the 3rd order nonlinear susceptibility
Sources: en.wikipedia.org
Evidence of application of poison derived from plants (likely from Boophone disticha) on the tips of 60,000-years-old arrowhead from the Umhlatuzana Rock Shelter (South Africa) is presented by Isaksson, Högberg & Lombard (2026). Arlt (2026) determines the Robberg stone tool tradition in southern Africa to span the internal from 24.800 to 9.700 years ago rather than from 18.000 to 12.000 years ago, and reports evidence of a more gradual transition between Robberg and Oakhurst technocomplexes than indicated by earlier studies. Review of research on the origin and on the course of global spread of Homo sapiens out of Africa from the preceding years is published by Groucutt (2026). Pantoja-Pérez et al. (2026) identify dental and bone abnormalities in the mandible of Qafzeh 25 as likely caused by sharp object trauma, and report evidence of survival of the studied individual after the injury. Litov, Ben-Dor & Barkai (2026) interpret the decline of use of in heavy-duty tools in Levant after the Lower-Middle Paleolithic transition, coinciding with decline of megaherbivores in the studied region, as indicating that the studied tools were primarily used for processing of large prey. Abbas et al. (2026) provide evidence from the study of riverine wetland environments from the Hamra Faddan and Wadi al-Hasa localities from the eastern margin of the Jordan Rift Valley interpreted as indicating that southern Levant provided a stable environmental niche that sustained human populations from the late Middle Paleolithic to the Upper Paleolithic. Zhao et al.
== Further reading == Khan, Misbah H.; Victor, Frank; Rao, Babar; Sadick, Neil S. (2010). "Treatment of cellulite. Part I. Pathophysiology". Journal of the American Academy of Dermatology. 62 (3): 361–70, quiz 371–2. doi:10.1016/j.jaad.2009.10.042. PMID 20159304. Khan, Misbah H.; Victor, Frank; Rao, Babar; Sadick, Neil S. (2010). "Treatment of cellulite. Part II. Advances and controversies". Journal of the American Academy of Dermatology. 62 (3): 373–84, quiz 385–6. doi:10.1016/j.jaad.2009.10.041. PMID 20159305.
Viscosity - The Feynman Lectures on Physics Fluid properties – high accuracy calculation of viscosity for frequently encountered pure liquids and gases Fluid Characteristics Chart – a table of viscosities and vapor pressures for various fluids Gas Dynamics Toolbox – calculate coefficient of viscosity for mixtures of gases Glass Viscosity Measurement – viscosity measurement, viscosity units and fixpoints, glass viscosity calculation Kinematic Viscosity – conversion between kinematic and dynamic viscosity Physical Characteristics of Water – a table of water viscosity as a function of temperature Calculation of temperature-dependent dynamic viscosities for some common components Artificial viscosity Viscosity of Air, Dynamic and Kinematic, Engineers Edge
Sources: en.wikipedia.org
A cannabinoid receptor modulator is a compound that bind to the cannabinoid receptors, which are receptors in the human body that regulate multiple physiological responses, including pain sensation, mood regulation, and appetite. The two main targets of cannabinoid receptors modulators are cannabinoid receptor 1 (CBR1) and cannabinoid receptor 2 (CBR2). By stimulating or inhibiting these receptors, the modulators can achieve different therapeutic effects, such as relieving pain, reducing vomiting, improving appetite and maintaining muscle tone. Dronabinol, nabiximol, cannabidiol and nabilone are cannabinoid receptor modulators marketed as drugs for various therapeutic uses. These drugs also share some common adverse effects, including dizziness, headache, alteration in mental state, and diarrhoea. Recent research studies have explored other therapeutic potentials of the modulators, such as the antitumor effect of cannabidiol. Other cannabinoid receptor modulators are also under investigations.
== Clinical trials == Remogliflozin etabonate was shown to enhance urinary glucose excretion in rodents and humans. Early studies in diabetics improved plasma glucose levels. Remogliflozin etabonate has been studied at doses up to 1000 mg. A pair of 12-week phase 2b randomized clinical trials of diabetics published in 2015, found reductions in glycated hemoglobin and that it was generally well tolerated. In a meta-analysis published by Dutta et al. involving data from 3 randomized controlled trials (535 patients), remogliflozin was noted to have similar glycaemic efficacy (reduction in HbA1c and fasting glucose) as compared to dapagliflozin and pioglitazone. A study concluded that concomitant administration of remogliflozin etabonate, either 500 mg or 750 mg BID (twice a day), with metformin 2000 mg BID was safe and effective in patients with type 2 diabetes mellitus during the observation period.
== Distribution and habitat == This species is found in parts of central and western Africa, in Burundi, Cameroon, Central African Republic, Democratic Republic of Congo, Republic of Congo, Equatorial Guinea, Gabon, Rwanda, and the province of Cabinda in Angola, as well as along the Burundian, Tanzanian and Zambian shores of Lake Tanganyika. It is largely an aquatic species and rarely is found far away from water. It can be found along lakes and rivers in forested and well-wooded savanna terrain where cover is sufficient, most commonly along lowland forested, bushy or wooded banks of lakes, rivers, and streams.
=== Tolerance dose === In 1931, the U.S. Advisory Committee on X-Ray and Radium Protection (ACXRP, now the National Council on Radiation Protection and Measurements, NCRP), founded in 1929, published the results of a study on the so-called tolerance dose, on which a scientifically based radiation protection guideline was based. Exposure limits were gradually lowered. In 1936 the tolerance dose was 0.1 R/day. The unit "R" (the X-ray) from the CGS unit system has been obsolete since the end of 1985. Since then, the SI unit of ion dose has been "coulomb per kilogram".
Sources: en.wikipedia.org
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, designed as a metabolically stabilized analogue of the endogenous tetrapeptide tuftsin. It has been studied mainly against anxiety-related and cognitive endpoints rather than as an approved medicine in most jurisdictions.
Tuftsin contains four residues, while selank carries an additional Pro-Gly-Pro segment at the carboxyl end. That extension is intended to reduce enzymatic cleavage. Comparative pharmacokinetic data in humans remain limited.
No single receptor target is widely accepted as the definitive mediator of the reported effects. Proposed contributors include GABAergic modulation, shifts in monoamine turnover, and altered neuropeptide degradation. The mechanism is treated in the literature as unresolved.
Intranasal administration predominates in both animal and human research because it avoids hepatic first-pass metabolism. Injectable and intraperitoneal routes appear in animal work mainly for comparison.